Question

Which of the following is the equation of the axis of symmetry of the quadratic equation y = 2x2 + 24x + 62?

x = –6

x = 6

x = –10

x = 10

Answer 1

for a parabola of \(\bf y = ax^2+bx+c\) type, you can always find the vertex at the coordinates of \(\bf \left(-\cfrac{b}{2a}\quad ,\quad c-\cfrac{b^2}{4a}\right)\)

so what's the vertex for \(\bf y = 2x^2 + 24x + 62\quad ?\)

Answer 2

a parabola with a squared "x" term, will go either upwards or downwards, so the axis of symmetry will be a vertical line, so the axis of symmetry will be given by the x-coordinate of the vertex only